Automerge dependabot pull requests

.github/workflows/on_pull_request.yml

@@ -0,0 +1,77 @@
+name: On pull request
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    continue-on-error: false
+    strategy:
+      max-parallel: 3
+      matrix:
+        composer:
+          - 1
+          - 2
+        php:
+          - 7.1
+          - 7.2
+          - 7.3
+          - 7.4
+          - 8.0
+          - 8.1
+    name: Test - php:${{ matrix.php }}; composer:${{ matrix.composer }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@master
+      - name: Install PHP
+        uses: shivammathur/setup-php@master
+        with:
+          php-version: ${{ matrix.php }}
+          extensions: curl, gd, pdo_mysql, json, mbstring, pcre, session
+          ini-values: post_max_size=256M
+          coverage: none
+          tools: composer:v${{ matrix.composer }}
+      - name: Composer validate
+        run: composer validate --strict --no-check-lock
+      - name: Install Composer dependencies (with dev)
+        run: composer install --no-progress --no-suggest --prefer-dist --optimize-autoloader
+      - name: Install Composer dependencies (without dev)
+        run: composer install --no-progress --no-dev --no-suggest --prefer-dist --optimize-autoloader
+
+  dependabot:
+    needs: tests
+    permissions:
+      pull-requests: write
+      contents: write
+    runs-on: ubuntu-latest
+    # Checking the actor will prevent your Action run failing on non-Dependabot
+    # PRs but also ensures that it only does work for Dependabot PRs.
+    if: ${{ github.actor == 'dependabot[bot]' }}
+    steps:
+      # This first step will fail if there's no metadata and so the approval
+      # will not occur.
+      - name: Dependabot metadata
+        id: dependabot-metadata
+        uses: dependabot/[email protected]
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+      # Here the PR gets approved.
+      - name: Approve a PR
+        run: gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      # Finally, this sets the PR to allow auto-merging for patch and minor
+      # updates if all checks pass
+      - name: Enable auto-merge for Dependabot PRs
+        # if: ${{ steps.dependabot-metadata.outputs.update-type != 'version-update:semver-major' }}
+        run: gh pr merge --auto --squash "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}